The role of gustatory flushing in Frey's syndrome and its treatment with botulinum toxin type A

Abstract

After parotid surgery, gustatory sweating and flushing occur more frequently, the former reportedly in 15-100% of cases, while no reliable data are available for the latter. Although botulinum toxin (BoNT) is effective in controlling sweating, little is known about its effect on flushing. In 17 patients suffering from Frey's syndrome after parotid surgery, we studied the gustatory flushing phenomenon as compared to gustatory sweating, analyzing their frequency, area, type of stimulus and response to BoNT administration. Cutaneous blood flow (CBF) was monitored by laser Doppler flowmetry (LDF) on affected and unaffected areas of the cheek in basal conditions and after meals, before and then 1 month after starting the BoNT injections. The Minor test was used to identify the sweating area. Flushing was observed in 7 of 17 patients after masticatory activity, spicy meals or citrus fruits. No clinical data correlated with any presence of flushing. Flushing regressed completely after BoNT administration and CBF reached similar values in the affected and unaffected sites. No adverse effects were observed. BoNT administration proved an effective and safe treatment for gustatory sweating and flushing in patients with Frey's syndrome.

Botulinum toxin type A injections: Adverse events reported to the US Food and Drug Administration in therapeutic and cosmetic cases

“…Indications not approved by FDA, but studied and reported in the medical literature, include extracervical spasticities, 8,9 especially for patients with cerebral palsy, [10][11][12][13][14][15][16] poststroke spasticity, 17,18 and piriformis syndrome. 19,20 Other reports describe off-label uses for a wide range of neurologic, [21][22][23][24][25][26] dermatologic, [27][28][29][30][31][32] gastrointestinal, [33][34][35][36][37][38][39][40][41][42] and other clinical [43][44][45][46][47][48][49][50][51] disorders, often without controlled clinical trials. Off-label use of a licensed drug or biologic product occurs with a wide range of products.…”

Botulinum Toxin for the Treatment of Refractory Erythema and Flushing of Rosacea

“…In a case series of 17 patients with Frey syndrome who received botulinum toxin A injections to affected areas, all patients experienced complete regression of gustatory sweating and flushing. The effects persisted for at least 7 months, with low to negligible recurrence rates [13]. The clinical results were substantiated with corresponding decreases in cutaneous blood flow, as measured using laser Doppler flowmetry [14].…”

New Uses of AbobotulinumtoxinA in Aesthetics

“…65,66 Frey’s syndrome is a neurological sequel to parotid surgery that causes sweating and flushing whenever saliva production is triggered. 71 These effects may be due to the inhibition by BoNT-A of acetylcholine and vasoactive intestinal polypeptide, and BoNT-A might therefore be an effective treatment for acne and rosacea. 65,66,72 …”